Fungi are an extremely diverse and widespread group of organisms, present in almost all ecological niches. They play an important role in the functioning of ecosystems and are also interesting because of the wide range of natural metabolites they produce. Many of these metabolites have potential insecticidal activity and could therefore be useful for the development of innovative biopesticides. We searched for crude mushroom extracts that exert a cytotoxic effect on the Sf9 cell line. Specifically, we were interested in those extracts that could potenitally harbour cytolytic proteins recognizing a membrane lipid receptor, and cosequentially leading to pore formation and cell death. Using the MTT cytotoxic test, we determined the insecticidal activity of various raw and heat-treated mushroom extracts against the insect cell line Sf9 and were the first to demonstrate the insecticidal potential of 18 mushroom species. We compared our results with previously obtained data on hemolytic activity and Sf9 total membrane lipid sedimination assay. Among the cytotoxic mushrooms, Megacollybia platyphylla, Bjerkandera adusta and Amanita excelsa proved to have the highest potential for the development of lipid-binding biopesticides. We have also demonstrated that the majority of insecticidal molecules are most probably produced by non-mycorrhizal fungi; therefore we propose that further research on new bioinsecticides should be focused on saprophytic and parasitic fungi.
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